Japanese author Kegio Hagashino is best known for his Detective Galileo mysteries. The latest in this series, Salvation of a Saint, is a deftly plotted police procedural that is not only a who-done-it, but also a how-done-it and a why-done-it. Plus, as seems to be popular in mysteries, there is a brilliant but eccentric outsider in the tradition of Sherlock Holmes who assists and frustrates the detectives charged with solving the crime.

The story begins with an argument between a husband and wife. Yoshitaka, the husband and company CEO, wants to have children but his wife and quilting teacher, Ayane, has yet to become pregnant after a year. So desperate for fatherhood, Yoshitaka callously asks for a divorce. Ayane is understandably upset about being thrown out like an old newspaper by the man she loves, and she thinks: "… your words were like a knife stabbing me in the heart. That's why you have to die too."

Yoshitaka does die, poisoned by ingesting arsenous acid, a form of arsenic, in his morning cup of coffee. Of course, Ayane would be the prime suspect, except she was far away from their home at the time of his death. With Ayane seemingly impossible as the murderer, other suspects emerge. Hiromi Wakayama, one of Ayane's quilt work students and Yoshitaka's lover, was apparently the last person to see him alive. One of Yoshitaka's colleagues, who has no love lost for the dead CEO, quickly assumes his position in the company.

The police investigtors are lead by Kusanagi, a stodgy and plodding but competent male detective, and his assistant, Utsumi, an up-and-coming young woman detective. When the detectives hit a dead-end in finding how the coffee was poisoned, Utsumi contacts the real star of the novel, physicist and professor Manabu Yukawa. She has to secretly meet him because her boss and the professor had a falling out. "Utsumi watched the professor's face while he talked. Kusunagi had said that the man they called Detective Galileo had always been very helpful when it came to working on a case. But something to do with one particular investigation had caused a rift between the detective and the physicist … though no one had told her any of the details."

Yukawa can't resist trying to solve the seemingly perfect crime. As he puts his brilliant mind to the task, the detectives continue their investigation. Eventually, he other suspects drop away, and they settle on the wife being the murderer, but since she was so far away from the crime scene, it does seem she has committed the perfect crime. Frustrated, Kusanagi reluctantly lets Yukawa consult on the case.

Following several leads and working on intuition as much as procedures, the detectives discover threads leading to the victim's past. Yukawa offers his insights and deductive reasoning, especially in determining how the poison got into the victim's coffee. Yukawa relishes explaining his counterintuitive logic in a way that greatly irritates Kusanagi.

The mystery works well, and the writing and translation are highly readable. To be a really great novel, the detective characters could have been more substantive, introducing some deeper moral and ethical issues. Perhaps in the next installments in the series, we will see some of that. But for mystery lovers, I would highly recommend the Detective Galileo series.

GailTodd, I am in the middle of reading this book, and I see one discrepancy in your review. Yoshitaka and Ayane had only been married one year when he asked for a divorce on account of Ayane not being pregnant yet.